Project Summary Young children?s essentialist views of gender (i.e., that gender is innate, immutable, informative, and discrete) are found to be inflexible in early childhood in all cultures studied to date, which has led researchers to construe of gender essentialism as an early-emerging cognitive default. The proposed work addresses the validity of this belief that gender essentialism is inevitable, by examining the development of gender essentialism among gender nonconforming and gender ?typical? children. Gender nonconforming children (those whose biological gender and internal sense of gender diverge) present a unique opportunity for answering this question, as their own gender identity defies central components of an essentialist outlook on gender (e.g., believing that gender is determined by one?s sex, that gender is discrete, etc). Thus, gender nonconforming children?s own experiences with gender might lead to early non-essentialist beliefs about gender, suggesting that broader theories about essentialism would need to be modified. In this work, we further expand our understanding of essentialism by asking whether essentialism is a domain-general or domain-specific cognitive bias. If essentialism is a domain-general capacity, we expect to find that gender essentialism is related to essentialism of other social categories (e.g., race) and natural kinds (e.g., animals). Further, if GNC children differ from gender typical children in their levels of gender essentialism, they will also differ in their levels of other essentialism. In contrast, if gender essentialism is domain-specific, any differences in gender essentialism will have no implication for other types of essentialism. Our third area of focus involves the socialization of gender essentialism, examining the extent to which gender nonconforming and gender typical children?s gender essentialism mirrors the messages they receive from their parents and communities about gender. Finally, we aim to examine the relation between gender essentialism and prejudice against gender nonconforming children among gender typical children. The literature provides conflicting evidence regarding the relation between essentialism of social categories and prejudice. Because gender nonconforming children tend to experience high levels of discrimination and prejudice by their peers, understanding this link has crucial implications for reducing peer victimization of gender nonconforming children. We will not only examine the link but will also test whether we can change children?s gender essentialism and if so, whether this will result in a reduction of bias against gender nonconforming children. Together this work will not only expand our theoretical understanding of essentialism, but will broaden our understanding of gender nonconformity in early childhood.